digital trigger source

[Kenn_N]

Tui,

Since you said you were quick to state that it didn't work.  What isn't working exactly?  You said at one point that you aren't getting any data, and that seems to mean that it doesn't work at all with the actual hardware.  I wanted to bring things back to square one and move forward until it breaks and thereby gain some insight as to why it is breaking. 

The DAQ Assistant is based on DAQmx, the advantage of using the actual native DAQmx API vi's is that it is easier to then add functionality into that vi in the furture.  For initial testing that I am discussing there wouldn't be much to gain from using MAX other than you can quickly change your settings in the task in MAX and re run the task quicker. 

Regards,

[Tui]

One further issue.  In addition to the loadcell data I also require Microphone data (AI on NI 9233)

When I create a task for this with a trigger on input 1 I get this error:

Error -89137 occurred at MySound PressureTask - DAQ Assistant

Possible Reason(s):

Specified route cannot be satisfied, because it requires resources that are currently in use by another route.

Property: Start.DigEdge.Src
Property: Start.DigEdge.Edge
Source Device: cDAQ2Mod5Di
Source Terminal: PFI1

Required Resources in Use by
Source Device: cDAQ2Mod5Di
Source Terminal: PFI0
Destination Device: cDAQ2
Destination Terminal: ai/StartTrigger

I am using Source Terminal: PFI0 for the loadcells, so does this mean that I can only use 1 Input trigger on the DI card?

[Kenn_N]

Hey Tui,

The Compact DAQ chassis is basically an M-Series card with changable front ends.  The chassis itself has similar limitations that an M-Series device has, such as the ability to trigger the Analog input engine only once, because you can only have one analog input task at a time.  So, when you asked me what the advantage was with using using the DAQmx API calls or the DAQ Assistant, this is one of those times.  You won't be able to run the seperate DAQ assistants, but you can setup one task, with all your different channels and run the system with one trigger.

I have attached a zip file with an example that does it.  I just wrote it so it may not be perfect, but it works with my simulated cDAQ chassis and modules.  Open the cDAQ - strain - microphone.vi, the other two are subvi's in that vi.  The reason for the subvi's is the channel setup takes up a lot of space so to see the example overview at a glance I made them subvi's.

Let me know if you have any further questions.

Regards,

Message Edited by Kenn N on 02-15-2007 08:06 AM

Message Edited by Kenn N on 02-15-2007 08:08 AM

[Kallis]

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@kenn N wrote:

The Compact DAQ chassis is basically an M-Series card with changable front ends.  The chassis itself has similar limitations that an M-Series device has, such as the ability to trigger the Analog input engine only once, because you can only have one analog input task at a time. 

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Kenn,

Thanks.That's something I didn't knew about cDAQ. When you say 'changable front end', did you mean the cDAQ module. So these chassis have similar DMA channels as is the case with M-series?

[Kenn_N]

Kallis,

Yes the changable front ends are the modules themselves.  And yes the DMA characteristics are the same as an M-Series device.  It's functionality is very similar to an M-Series USB device like the USB-6251.  Let me know if you have any further questions.

Regards,